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| author | Filipe Manana <fdmanana@suse.com> | 2024-11-04 12:11:15 +0000 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2024-11-14 13:15:17 +0100 |
| commit | 2cb1a73d1d44a1c11b0ee5eeced765dd80ec48e6 (patch) | |
| tree | 2029346b0c1e68c8aced301cb418ae7262ff1b67 /fs/btrfs | |
| parent | ba884534f1e97571db082da9878fdeefdcb2a01c (diff) | |
| download | linux-2cb1a73d1d44a1c11b0ee5eeced765dd80ec48e6.tar.gz linux-2cb1a73d1d44a1c11b0ee5eeced765dd80ec48e6.tar.bz2 linux-2cb1a73d1d44a1c11b0ee5eeced765dd80ec48e6.zip | |
btrfs: reinitialize delayed ref list after deleting it from the list
commit c9a75ec45f1111ef530ab186c2a7684d0a0c9245 upstream.
At insert_delayed_ref() if we need to update the action of an existing
ref to BTRFS_DROP_DELAYED_REF, we delete the ref from its ref head's
ref_add_list using list_del(), which leaves the ref's add_list member
not reinitialized, as list_del() sets the next and prev members of the
list to LIST_POISON1 and LIST_POISON2, respectively.
If later we end up calling drop_delayed_ref() against the ref, which can
happen during merging or when destroying delayed refs due to a transaction
abort, we can trigger a crash since at drop_delayed_ref() we call
list_empty() against the ref's add_list, which returns false since
the list was not reinitialized after the list_del() and as a consequence
we call list_del() again at drop_delayed_ref(). This results in an
invalid list access since the next and prev members are set to poison
pointers, resulting in a splat if CONFIG_LIST_HARDENED and
CONFIG_DEBUG_LIST are set or invalid poison pointer dereferences
otherwise.
So fix this by deleting from the list with list_del_init() instead.
Fixes: 1d57ee941692 ("btrfs: improve delayed refs iterations")
CC: stable@vger.kernel.org # 4.19+
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'fs/btrfs')
| -rw-r--r-- | fs/btrfs/delayed-ref.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/fs/btrfs/delayed-ref.c b/fs/btrfs/delayed-ref.c index e08e3852c478..99a78ca28db2 100644 --- a/fs/btrfs/delayed-ref.c +++ b/fs/btrfs/delayed-ref.c @@ -622,7 +622,7 @@ static int insert_delayed_ref(struct btrfs_trans_handle *trans, &href->ref_add_list); else if (ref->action == BTRFS_DROP_DELAYED_REF) { ASSERT(!list_empty(&exist->add_list)); - list_del(&exist->add_list); + list_del_init(&exist->add_list); } else { ASSERT(0); } |